Multistage axial-flow steam or gas turbine



P. SPIESS.

MULT ISTAGE AXIAL FLOW STEAM 0R GAS TURBINE. APPLICATION FILED MAR. 31.192].

1, 389,910, PatentedSept. 6, 1921.

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PATENT OFFICE.

PAUL SPIESS, OF ZIl'RICI-I, SWITZERLAND.

MULTISTAGE AXIAL-FLOW STEAM OR GAS TURBINE.

Specificationof Letters Patent.

Patented Sept. 6, 1921.

Application filed March 31, 1921. Serial No. 457,343.

(GRANTED UNDER. THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L,1313.)

T 0 all whom it may concern:

Be it known that I, PAUL Srmss, a citizen of the Republic ofSwitzerland, residing at Zurich, Switzerland, have invented certain newand useful Improvements in Multistage Axial-F low Steam or Gas Turbines,(for which I have filed applications in Switzerland, Feb. 6, 1917,Patent No. 76,010; England, Jan. 31, 1918, Patent No. 113,273; Germany,Feb. 10, 1917, utility model 681,589; France, Jan. 23, 1918, Patent No;188,588 and I do hereby declare the following to be a clear, full, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawing, and to letters or figures ofreference-marked thereon, which form a part of this specification.

This invention has reference to guide channels for multistage, axialflow steam or gas turbines adapted to direct the driving medium from onerotor wheel or runner to another rotor wheel or runner having aconsiderably difl'erentdiameter. In a turbine according to the inventiona guide channel of S-shaped longitudinal section in a plane passingthrough the turbine axis with an entirely axially directed inlet and anentirely axially directed outlet for conveying the driving medium fromone rotor wheel to a similar one of considerably different diameter hasarranged within it at least one partition or guide wall corresponding tothe said sectional shape of the channel, the rotor wheels being of theusual type the blades of which extend without obstruction from the rotordisk periphery to the bounding rings, the arrangement being such thatthe total quantity of steam or gas working on the blades of one rotorwheel is guided over to the blades of the next following rotor wheel insuch-wise that all the steam entering the said next ring of blades isdirected axially as far as possible, and thus possesses a radialcomponent as low as possible. The said partition or guide wall may insome cases extend only over the first portion of the length or" thechannel.

In guide channels which have to direct the driving medium from one rotorwheel to another having a considerably different mean diameter, forinstance a considerably greater mean diameter, and into which thedriving medium disturb each other when the direc-' tion of the middleline of the channel, seen in longitudinal section, in a'plane passingthrough'the turbine axis, changes, and that said layers cause eddies andlower consequently the eiiiciency of the turbine.

This drawback is largely remedied by the present invention.

1 am aware that it has already been proposed to provide in steamturbines annular guide walls for separating into annular portions thesteam flowing from a number of rows of moving blades to the exhaust andalso for guidingand separating into annular portions the steam flowinfrom a portion of one set of moving blades to another set. Incontradistinction to such a construction however each current of steamthat has done duty in the moving blades of one rotor wheel is, accordingto the present invention, guided completely to the moving blades of 'thenext following rotor wheel, care being taken that such steam strikes thesaid moving blades in an axial direction, that is to say the current ofsteam has as small a radial component as possible when it impinges onthe said blades.

The accompanying drawing illustrates diagrammatically two embodiments ofthe invention. The two figures represent longitudinal sections in aplane passing through the turbine axis through the parts carrying theblades of a steam turbine comprising six pressure-stages and in whichthe three last stages have a considerably greater mean wheel-diameterthan the three first stages. Into the intermediate guide channel areinserted guidewalls. The steam flows from the left to the right handside.

In Figure 1, it will be seen that the rotor wheels 1, 2 and 3 haveapproximately the same mean diameter d and that the rotor wheel a, has adiameter D, the latter being considerably greater than the diameter (Z.Within the intermediate guide channel 7 is arranged a guide wall 8extending over the entire length of the channel.

According to the embodiment shown in Fig. 2, three guide walls 13, 14and 15 are provided only on the first portion of the uide channel 12 intheintermediate disk 11.

' zlompared' with the construction shown in Fig. 1, said shorter wallsoffer the advantage that they oppose less frictional resistance to thesteam flowing through the channel. In spite of their shortness, they areyet able to guide the steam in a sufiiciently satisfactory manner.

It is obvious that before entering the rotor wheels at the end of theS-shaped channels,

the steam will be suitably directed by means of guide blades'arranged inthese channels. a I claim:

1. In a multistage axial flow steam or gas turbine having a guidechannel S-shaped 'in'longitudinal axial section for conveying thedriving medium from one rotorwheel to a similar one of considerablydiflerent diameter; a partition or guide wall arranged within thischannel, said partition having a form corresponding to the sectionalshape of the channel, the rotor wheels being of the usual type havingblades that extend without obstruction from the rotor disk peripherytothe bounding rings, whereby the total quantity of steam or gas workingon the 7 blades of one wheel is guided over to the blades of the nextfollowing rotor wheel.

2. In a multista e axial flow steam or as turbine having a guide channelS-oshaped J in longitudinal axial section for conveying thedriving'medium from one rotor wheel to a similar one of considerablydiiferent d1- ame'ter, said channel having an entirely axiallydirected'inlet and an'entirely axially directed outlet, a partition orguide wall arranged within said channel, said partition? having a formcorresponding. to the sectional shape of the channel, the rotor wheelbeing of the usual type having blades that a similar one of considerablydifferent di-' ameter, saidchannel having-an entirely axially directedinlet and an entirely axially directed outlet, apartit-ion or guide wallarranged within said channel and extended. only over a portion of saidchannel, said par tition having a form corresponding to the sectionalshape of the channel, the rotor wheel being of the usual type havingblades that extend without obstruction from the rotor disk periphery tothe bounding ring, whereby. the total quantityv of steam or'gas workingon the blades of one rotor wheel is guided over to the: blades of thenext follow.

ing rotor wheel to cause allthe steam entering: the said next ring ofblades to be directedaxially as far as possible 'andthus pos- Intestimony that- I claim the foregoing as my nvention, I'have signed myname.

PAUL 'srrnss.

,sesses a radial component as low as possible.

